on my wordpress site I have WooCommerce and the WooCommerce per product shipping extension (https://docs.woocommerce.com/document/per-product-shipping/). I currently have an issue, this is that whenever I duplicate a woocommerce product the per-product shipping information is not copied. I have tried to find a solution for this and have got the following code however I have not been able to get it work, can anyone see what is going wrong in the following